The territory of Castellar in the Alpes-Maritimes department stretches from north to south between the Italian border east and the Careï valley to the west. It essentially consists of forests and semi-natural environments, covering 93.4% of its 3,024 acres (1,224 ha). Forests occupy 50.4%, areas with shrubby or herbaceous vegetation 33.5%, and open spaces with little vegetation 9.5%. The human impact is relatively low on Castellar's territory since the urbanized and agricultural areas only represent 6.1% and 0.5% of the municipal land.